Spatial and cortical influences exerted on cuneothalamic and thalamocortical neurons of the cat

Canedo, Antonio; Aguilar, Juan

doi:10.1046/j.1460-9568.2000.00107.x

Cited by 48 publications

(55 citation statements)

References 71 publications

(99 reference statements)

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“…3, A and B) in the majority of experiments we observed an increase of the power provoked by the cortex stimulation. This result agrees with the previously reported facilitation of the stimulus response provoked by the SI cortex stimulation (Aguilar et al 2003;Canedo and Aguilar 2000;Nuñez 1998, 2004). To quantify the percentage of the neurons exhibiting different types of the effect of stimulation of the SI cortex we evaluated the number of increases of the spectral power or I-effects, the number of No-effects (when the difference was negligible), and the number of decreases or D-effects.…”

Section: Spectral Changes In the Neural Response Provoked By Electricsupporting

confidence: 93%

“…Thus the rhythmic synchronization may increase the contrast between the evoked EPSPs from rhythmically entrained neurons and the synaptic outputs from noncoherent neurons. A selective facilitating effect of the corticofugal feedback has been previously described in the somatosensory system (Canedo and Aguilar 2000;Nuñez 1998, 2004) and in other sensory pathways (see e.g., Jen et al 2002;Sillito et al 1994;Yan and Suga 1996). The facilitating effect is due to the activation of NMDA receptors in gracile neurons (Malmierca and Nuñez 2004;Nuñez and Buño 2001).…”

Section: Discussionmentioning

confidence: 78%

“…Recently, it has been reported that the sensorimotor cortex exerts a selective control of the somatosensory transmission at the DCN (Aguilar et al 2003;Canedo and Aguilar 2000;Nuñez 1998, 2004). Indeed, the corticofugal input facilitates sensory responses of gracile neurons with overlapping receptive fields and inhibits sensory responses of cells with separate receptive fields, probably providing a synaptic mechanism for the enhancement of contrast between sensory signals.…”

Section: Introductionmentioning

confidence: 99%

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Corticofugal Modulation of the Tactile Response Coherence of Projecting Neurons in the Gracilis Nucleus

Castellanos

Malmierca²,

Núñez³

et al. 2007

Journal of Neurophysiology

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Castellanos NP, Malmierca E, Nuñ ez A, Makarov VA. Corticofugal modulation of the tactile response coherence of projecting neurons in the gracilis nucleus. J Neurophysiol 98: [2537][2538][2539][2540][2541][2542][2543][2544][2545][2546][2547][2548][2549] 2007. First published August 29, 2007; doi:10.1152/jn.00815.2007. Precise and reproducible spike timing is one of the alternatives of the sensory stimulus encoding. We test coherence (repeatability) of the response patterns elicited in projecting gracile neurons by tactile stimulation and its modulation provoked by electrical stimulation of the corticofugal feedback from the somatosensory (SI) cortex. To gain the temporal structure we adopt the wavelet-based approach for quantification of the functional stimulus-neural response coupling. We show that the spontaneous firing patterns (when they exist) are essentially random. Tactile stimulation of the neuron receptive field strongly increases the spectral power in the stimulus and 5-to 15-Hz frequency bands. However, the functional coupling (coherence) between the sensory stimulus and the neural response exhibits ultraslow oscillation (0.07 Hz). During this oscillation the stimulus coherence can temporarily fall below the statistically significant level, i.e., the functional stimulus-response coupling may be temporarily lost for a single neuron. We further demonstrate that electrical stimulation of the SI cortex increases the stimulus coherence for about 60% of cells. We find no significant correlation between the increment of the firing rate and the stimulus coherence, but we show that there is a positive correlation with the amplitude of the peristimulus time histogram. The latter argues that the observed facilitation of the neural response by the corticofugal pathway, at least in part, may be mediated through an appropriate ordering of the stimulus-evoked firing pattern, and the coherence enhancement is more relevant in gracilis nucleus than an increase of the number of spikes elicited by the tactile stimulus.

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Section: Spectral Changes In the Neural Response Provoked By Electricsupporting

confidence: 93%

Section: Discussionmentioning

confidence: 78%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Corticofugal Modulation of the Tactile Response Coherence of Projecting Neurons in the Gracilis Nucleus

Castellanos

Malmierca²,

Núñez³

et al. 2007

Journal of Neurophysiology

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“…Similar mechanisms have been suggested to operate in both the somatosensory [57][58][59][60] and the auditory [5] systems.…”

Section: Functional Aspects Of Thalamocortical Interactionsmentioning

confidence: 55%

Looking back: corticothalamic feedback and early visual processing

Cudeiro

Sillito

2006

Trends in Neurosciences

120

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“…Corticofugal positive feedback on subcortical matched neurons and negative feedback (lateral inhibition) on unmatched neurons have been found in the auditory (1, 2), visual (34), and somatosensory (35,36) systems. Furthermore, it has been found that the modulation of neurons in the dorsal column nuclei and ventroposterolateral nucleus of the somatosensory system by neurons in the motor cortex consists of the excitatory effect on neurons with a receptive field topographically corresponding (i.e., matched) to the joint controlled by neurons in the motor cortex and the inhibitory effect on these with the receptive fields topographically unmatched to that joint (37).…”

Section: Discussion Corticofugal Modulation and Shifts In Tuning Curvmentioning

confidence: 99%

Reorganization of the auditory cortex specialized for echo-delay processing in the mustached bat

Xiao¹,

Suga²

2004

Proc. Natl. Acad. Sci. U.S.A.

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Focal excess sensory stimulation evokes reorganization of a sensory system. It is usually an expansion of the neural representation of that stimulus resulting from the shifts of the tuning curves (receptive fields) of neurons toward those of the stimulated neurons. The auditory cortex of the mustached bat has an area that is highly specialized for the processing of target-distance information carried by echo delays. In this area, however, reorganization is due to shifts of the delay-tuning curves of neurons away from those of the stimulated cortical neurons. Elimination of inhibition in the target-distance processing area in the auditory cortex by a drug reverses the direction of the shifts in neural tuning curves. Therefore, such unique reorganization in the time domain is due to strong lateral inhibition in the highly specialized area of the auditory cortex.bicuculline ͉ centrifugal shift ͉ centripetal shift ͉ delay tuning ͉ plasticity E lectric stimulation of cortical auditory neurons evokes both facilitation and inhibition of the auditory responses of cortical and subcortical neurons. The amount of facilitation and inhibition varies with the frequency of a tone burst to which the neurons respond and with the relationship in frequency tuning between the stimulated and recorded neurons. When the best frequency (BF) of a recorded neuron matches that of a stimulated cortical neuron, the response of the matched neuron to its BF is often augmented, and the responses at frequencies lower and͞or higher than the BF are inhibited. When unmatched, the response of the unmatched neuron is inhibited at its BF and is facilitated at non-BFs. As a result, frequency tuning of the unmatched neuron is shifted. The shift of a BF, together with a frequency-tuning curve, is called a BF shift. Such corticofugal modulation, called egocentric selection (1), improves the input to the stimulated cortical neurons and the subcortical and cortical representations of the stimulus parameters to which the stimulated cortical neurons are tuned (2)(3)(4)(5)(6)(7)(8) There are two types of BF shifts: centripetal and centrifugal. Centripetal BF shifts are the shifts toward the BF of electrically stimulated cortical neurons, and centrifugal BF shifts are the shifts away from the stimulated cortical BF. These two types of BF shifts occur in a specific spatial pattern along the frequency axis in the auditory cortex (AC), medial geniculate body, and inferior colliculus. The spatial pattern is basically the same in the AC and the inferior colliculus of the big brown bat (3,5,6,9) and the mustached bat (1, 2, 10). In the ACs of the big brown bat (5, 6) and Mongolian gerbil (8), centripetal BF shifts occur in a large area surrounding the matched neurons, and small centrifugal BF shifts occur in the narrow zone surrounding this large centripetal area; i.e., center-surround reorganization occurs. Because centrifugal BF shifts are small, the major reorganization in these ACs is due to centripetal BF shifts. In the Doppler-shifted constant frequency (DSCF)...

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Spatial and cortical influences exerted on cuneothalamic and thalamocortical neurons of the cat

Cited by 48 publications

References 71 publications

Corticofugal Modulation of the Tactile Response Coherence of Projecting Neurons in the Gracilis Nucleus

Corticofugal Modulation of the Tactile Response Coherence of Projecting Neurons in the Gracilis Nucleus

Looking back: corticothalamic feedback and early visual processing

Reorganization of the auditory cortex specialized for echo-delay processing in the mustached bat

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